Expander Roller for Fold-Free Expansion of Foils

ABSTRACT

An expander roller for a fold-free expansion of foils, webs, and sheet materials in a width dimension. The expander roller has a central metal axle mounted in a surrounding synthetic tube with placed on its circumference a grid of implanted brush plugs in an axial direction under an angle alpha and with a mutual distancing and in tangential direction under a center angle beta and with a mutual distance. The roller provides a perfect expanding or stretching of thin widths of different materials.

The present invention concerns an expander roller for fold-free expansion of foils, widths of paper or textile e.g. This expander roller with length L obliquely implanted with elastic brush plugs at his outer circumference in order to spread said foils or widths of different materials.

BACKGROUND OF THE INVENTION

Such an expander roller is known by the German Patent DE102004 038 165.8, filed Jun. 8, 2004, titled: “Verfahren zum Spreizen von laufenden Bahnen”, inventor Rolf Hessenbruch, Remscheid, Germany. This patent describes a method and device formed as a roller in order to spread thin widths of material, which are forced to move over the circumference of said roller covered with brush plugs. Mentioned spreading of expanding roller device has obliquely implanted elastic brush plugs in rows. These rows of brush plugs are obliquely implanted from the middle of the axle to the left and to the right of the support structure. Then the known expander roller has some further modifications in implanting the brush parts in an elliptic way around the circumference of the roller (figure 8) in order to create a bigger distance between the row of brush plugs. This creates a spread in motion and cross direction of the thin width or foils. The surface of the brush plug has somewhat the shape of a wave and is firstly obliquely cut in the axial direction of the roller.

A drawback is, that the very intensive placing or mounting of the brush plugs in intensive rows on the circumference react to an incomplete and not uniform spreading or expanding force on the foils or widths, which widths forced under pressure around a segmental part of the expander roller. Furthermore, due to the intensive placing of the brush plugs in general, with little intermediate distance, the production costs will increase, which is not a very economical solution. This also applies to the elliptical placing of the brush plug around the circumference of the expander roller. It is rather complicated and it does not have the desired effect.

OBJECT OF THE INVENTION

Therefore the aim of our invention is to overcome mentioned drawbacks and to provide an expander roller that operates more efficiently and is less costly to manufacture.

SUMMARY OF THE INVENTION

The expander roller according to the invention for the fold-free expansion of foils e.g. is characterized in that said expander roller is a type built-up roller tube with a total circumference radius R, a usable length of 2×L/2 and placed with his ends in a support structure for free rotation, wherein said circumference surface consists of a grid of obliquely implanted brush plugs with a free length t, wherein said brush plugs form an angle alpha (α) in axial direction of length L/2 to the two ends of the expander roller with the vertical placed on the outer circumference and with an angle partly beta (β=α/p) with the normal in the tangential direction, wherein the mutual centre distance of the brush plugs in the rows is X in said axial direction, wherein the mutual distance of said radial distances of the brush plugs is determined by the centre angle beta (β) and the radius r of the expander roller and wherein each following axial row of brush plugs on the circumference is shifted ½× to each other in axial direction.

The advantage is a very economical executed expander roller, that in practice operates to expand thin material widths with better results.

Furthermore the expander roller according to the invention is developed in such a way, characterized in that the dimensions of the expander roller for R is between 50 mm and 500 mm, preferably 200 mm, r is between 25 mm and 400 mm, preferably 150 mm and L is between 1000 mm and 5000 mm, preferably 2500 mm in which said angle alpha (α) is between 7 degrees and 25 degrees, preferably 12 degrees and said angle partly beta (β=α/p) is between 0.2 alpha and 0.5 alpha, preferably 0.25 alpha.

The advantage is that for each application an optimal solution can be produced in an economical way by varying X and the angle β.

Next, the expander roller according to the invention is developed in such a way, characterized in that said length t of the obliquely implanted brush plugs is between 5 mm and 25 mm, preferably 12 mm and wherein the material of the obliquely bended brush roller is a synthetic material such as polypropylene, wherein the diameter of said plug thread is between 0.1 mm and 0.8 mm, preferably 0.25 mm.

The advantage is brush plugs which can be adapted for optimal application in the spreading of all kinds of material widths.

BRIEF DESCRIPTION OF THE DRAWING

A preferred embodiment of the present invention will now be described with reference to the accompanying drawing, in which:

FIG. 1 shows an axial section of the expander roller according to the invention;

FIG. 2 shows a partial side view with only three rows represented with brush plugs according to the invention;

FIG. 3 shows a cross-section over the line III-III of FIG. 2; and

FIG. 4 shows a top view over the line IV of FIG. 2 to show the grid of the brush plugs.

FIG. 1 represents an axial section of the expander roller 1 according to the invention. The expander roller 1 is built up with a central axle 2, which ends 3 are placed in a support structure (not shown) for free rotation. A tube 4 of a mostly synthetic material, such as polypropylene, is mounted around said central axle 2. Mentioned tube structure 4 can be made as a tube or in cylindrical parts. The brush parts 5 are implanted in bore holes in the circumference of tube structure 4 with special machines. As can been seen in FIG. 2, from halfway of the axle 2 the brush parts 5 are placed under an angle alpha (α) in the left L/2 part to the left and in de right L/2 part to the right for the expanding or stretching procedure. The angle alpha (α) is between 7 degrees and 25 degrees, preferably 12 degrees. The distance X is between 5 mm and 15 mm, preferably 10 mm. The distance βr is due to the radius r and angle beta (β). For different applications of expanding or spreading foils, widths of different materials, the measurements X and βr can be adapted to an optimum for special use.

FIG. 2 represents a partial side view with only three rows with brush plugs 5. For identical parts identical numbers are used.

FIG. 3 represents a cross-section over the line III-III of FIG. 2. In the cross-section the foil 6 or other thin material to expand or stretch is forced around a segmental part of the expander roller 1. Some of the brush plugs 5 are deformed for the expanding or stretching operation. The total radius R is diminished to R-AR. The free length t of the brush plugs 5 is between 5 mm and 25 mm, preferably 12 mm.

FIG. 4 represents a top view over the line IV of FIG. 2 to show the grid op the brush plugs. Identical parts are indicated with identical numbers. Finally is has to be emphasized, that a preferred embodiment of the invention is described an that it is self-evident that further modifications are possible without leaving the scope of this invention. 

1. Expander roller with working length L and on an outer circumference surface oblique implanted elastic brush plugs are placed, which are halfway the length L obliquely implanted to opposite ends of said expander roller for expanding or stretching widths of thin materials, foils and webs, wherein said expander roller is a built-up roller tube with a total circumference radius R, a usable length of 2×L/2 and with said opposite ends placed in a support structure for free rotation, wherein said circumference surface has a grid of said obliquely implanted brush plugs with a free length t, wherein said brush plugs form an angle alpha (α) in axial direction over length L/2 to the opposite ends of the expander roller with a vertical placed on the outer circumference surface and with an angle partly beta β(β=α/p) with a normal in a tangential direction thereof, wherein a mutual center distance of the brush plugs in the rows is X in said axial direction, wherein a mutual distance of said radial distances of the brush plugs is determined by the center angle beta (β) and radius r of the expander roller and wherein each following row of brush plugs on the circumference surface is shifted ½× to each other in axial direction.
 2. Expander roller as in claim 1, wherein said built-up expander roller has an central axle which is surrounded by a synthetic tube in order to contain said brush plugs on its radius r.
 3. Expander roller as in claim 1, wherein the dimensions of the expander roller for R is between 50 mm and 500 mm, preferably 200 mm, r is between 25 mm and 400 mm, preferably 150 mm and L is between 1000 and 5000 mm, preferably 2500 mm.
 4. Expander roller as in claim 1, wherein said angle alpha (α) is between 7 degrees and 25 degrees, preferably 12 degrees and said partly angle beta β (β=α/p) is between 0.2 alpha and 0.5 alpha, preferably 0.25 alpha.
 5. Expander roller as in claim 1, wherein said distance X is between 5 mm and 15 mm, preferably 10 mm.
 6. Expander roller as in claim 1, wherein said length t of the obliquely implanted brush plugs is between 5 mm and 25 mm, preferably 12 mm.
 7. Expander roller as in claim 6, wherein the material of the obliquely bended brush roller is a synthetic material such as polypropylene, wherein the diameter of said plug thread is between 0.1 mm and 0.8 mm, preferably 0.25 mm.
 8. Expander roller as in claim 1, wherein the bending strength of the brush plugs from the center of the expander roller up towards the end varies and increases for special applications.
 9. Expander roller as in claim 1, wherein the ends of the expander roller is freely rotating in the support structure.
 10. Expander roller as in claim 1, wherein said brush plugs are obliquely cut off in axial direction of the expander roller. 